Allan Ferguson Duncan was born in Glen Bank, Port Glasgow, Scotland on 21 May 1870 and was articled to William Clarke (1809-1889) and George Bell of Clarke & Bell in Glasgow in 1892 and remained with them as their assistant until 1903 when he commenced independent practice as an architect in Glasgow.
He was in partnership with George Donaldson Copland (1874-1938) as Duncan & Copland from 1903 to 1938. Duncan was elected a Licentiate of the Royal Institute of British Architects (LRIBA) in 1911. He lived and worked in Glasgow throughout his career as an architect. He died in Glasgow on 2 August 1941
See: Dictionary of Scottish Architects 1660-1980 [link below]
Directory of British Architects 1834-1914. Compiled by Antonia Brodie, et al. Volume 1: A-K. London; New York: British Architectural Library, Royal Institute of British Architects/Continuum, 2001